1. Technical Field
The present invention relates to an acid gas separation module and a method for manufacturing an acid gas separation module.
2. Background Art
In recent years, development of techniques for selectively separating carbon dioxide from a mixed gas is advancing. For example, as a countermeasure for global warming, a technique of collecting carbon dioxide in exhausted gas and condensing it, and a technique of forming a complex for carbon dioxide separation, which is used for obtaining gas for fuel cells or the like, the gas including hydrogen as a main component, by reforming a hydrocarbon into hydrogen and carbon monoxide (CO) by steam reforming, further allowing the carbon monoxide to react with steam to form carbon dioxide and hydrogen, and excluding the carbon dioxide by using a membrane which is selectively permeable by carbon dioxide, have been developed. Further, various techniques of separating acidic gases such as toxic hydrogen sulfide, have also been developed. In an example of an acidic gas separation module having carbon dioxide separation ability, a carbon dioxide separation module, which is densely filled with a carbon dioxide complex in order to process a larger amount of gas using a small volume, is equipped with a complex for carbon dioxide separation including a support which serves as a flow channel material that is permeable by gas, a carbon dioxide separation layer containing a carbon dioxide carrier, and a porous membrane having gas permeability, and using the carbon dioxide separation module, carbon dioxide in the gas is separated by the function of the carbon dioxide separation layer, and removed, while the gas passes through the voids of the support.
In general, in order to efficiently perform separation of acidic gas by using a complex for acidic gas separation, plural layers of a complex for acidic gas separation are disposed one on another in layers and used. Specifically, a cylindrical spiral-wound module for acidic gas separation produced by winding, on a perforated hollow central tube, a layered body including a complex for acidic gas separation and a flow channel material is used.
For example, a method for manufacturing a carbon dioxide separation gel membrane, in which an aqueous solution of an non-crosslinked vinyl alcohol-acrylic acid salt copolymer is coated on a carbon dioxide permeable support so as to form a film, followed by crosslinking by heating, to obtain a water insoluble substance, and then this water insoluble substance is impregnated with an aqueous solution of a carbon dioxide carrier and gelated, has been disclosed (for example, see Japanese Patent Application Publication (JP-B) No. H7-102310).
In a separation membrane module, a flow channel material having a network structure is disposed adjacent to an acidic gas separation layer, in order to provide flow paths for the acidic gas and the gas to be processed. When pressure loss occurs in the flow channel material, separation efficiency lowers, and therefore, a technique of setting different values for the thread diameters of warp and weft, in the threads that form the network structure, and a technique of thinning the thread diameter only at the intersection portion, have been proposed (see, for example, Japanese Patent Application Laid-Open (JP-A) Nos. 2007-117949 and 2010-131483).